All verses are quoted from the NASB anything in [square brackets] is added by me for clarity.

"Do not store up for yourselves treasures on earth, where moth and rust destroy, and where thieves break in and steal. But store up for yourselves treasures in heaven, where neither moth nor rust destroys, and where thieves do not break in or steal; for where your treasure is, there your heart will be also." Matthew 6:19-21

Jesus commands us to store up treasures in heaven. The obvious question is - How do we store up treasures in heaven? In the following verses we are given some ways of doing this.

"But when you give to the poor, do not let your left hand know what your right hand is doing, so that your giving will be in secret; and your Father who sees what is done in secret will reward you." Matthew 6:3 & 4

"Jesus said to him, `If you wish to be complete, go and sell your possessions and give to the poor, and you will have treasure in heaven; and come, follow Me.' " Matthew 19:21 [cf. Luke 18:22]

"Sell your possessions and give to charity; make yourselves money belts which do not wear out, an unfailing treasure in heaven, where no thief comes near nor moth destroys. For where your treasure is, there your heart will be also." Luke 12:33 & 34

So secretly giving to charity is one way.

"But you, when you pray, go into your inner room, close your door and pray to your Father who is in secret, and your Father who sees what is done in secret will reward you." Matthew 6:6

Praying in secret is another way.

"But you, when you fast, anoint your head and wash your face so that your fasting will not be noticed by men, but by your Father who is in secret; and your Father who sees what is done in secret will reward you." Matthew 6:17 & 18

Fasting in secret is still another way.

"He who receives a prophet in the name of a prophet shall receive a prophet's reward;" Matthew 10:41a

By letting a prophet stay in your house, in his name, is another way. The verse continues -

"and he who receives a righteous man in the name of a righteous man shall receive a righteous man's reward." Matthew 10:41b

By letting a righteous man stay in your house, in his name, is another way. The passage continues -

"And whoever in the name of a disciple gives to one of these little ones even a cup of cold water to drink, truly I say to you, he shall not lose his reward." Matthew 10:42 [cf. Mark 9:41]

"And everyone who has left houses or brothers or sisters or father or mother or children or farms for My name's sake, will receive many times as much, and will inherit eternal life. But many who are first will be last; and the last, first." Matthew 19:29 & 30 [cf. Mark 10:29-31 & Luke 18:29 & 30]

You need to follow Jesus first to get into heaven (so you can get a reward there).

Right after telling us to "love our enemies", Jesus said,

"For if you love those who love you, what reward do you have? Do not even the tax collectors do the same?" Matthew 5:46

"But love your enemies, and do good, and lend, expecting nothing in return; and your reward will be great, and you will be sons of the Most High; for He Himself is kind to ungrateful and evil men." Luke 6:35

So loving your enemies is another way to get a great reward in heaven. Please notice that this reward is in heaven, and now look at what it says a few verses later -

"Give, and it will be given to you. They will pour into your lap a good measure--pressed down, shaken together, and running over. For by your standard of measure it will be measured to you in return." Luke 6:38

So this verse is also talking about getting a reward in heaven, not on earth like some people claim.

"Blessed are you when men hate you, and ostracize you, and insult you, and scorn your name as evil, for the sake of the Son of Man. Be glad in that day and leap for joy, for behold, your reward is great in heaven." Luke 6:22 & 23a

So by being insulted because of Jesus is another way of storing up treasures in heaven!